The present invention relates generally to sensors and actuators.
For safety concerns, many of today""s vehicles are equipped with anti-lock brake systems (ABS). An ABS maintains vehicle control during extreme braking by preventing the wheels from locking up and slipping on the road surface. The ABS maintains vehicle control by electronically sensing when the wheels are just about to lock up and releasing the brakes before lock up occurs. An ABS is capable of modulating the pressure in the wheel cylinders in order to keep the wheels just under slip conditions.
Modern ABS electronically sense when the wheels are just about to lock up and release the brakes before lock up occurs. These systems are capable of modulating the pressure in the wheel cylinders in order to keep the wheels just under peak slip conditions. In general, a typical modern anti-lock brake system includes an electronic control unit, a wheel speed sensor located at each wheel, and a solenoid valve for controlling the hydraulic pressure in each wheel cylinder.
One type of speed sensor is a wheel bearing speed sensor in which the sensor is mounted in a wheel bearing that supports a rotating shaft to which the wheel is attached. Unfortunately, if the wheel bearing speed sensor is damaged or fails, not only must the defective speed sensor be replaced, the wheel bearing must also be replaced resulting in considerable extra cost.
The present invention has recognized the above drawbacks, and has provided the below-disclosed solutions to one or more of these deficiencies.
A steering knuckle sensor assembly includes a steering knuckle that forms a first bore and a second bore that leads to the first bore. A shaft is disposed within the first bore and rotates with respect to the steering knuckle. Moreover, a target ring circumscribes the shaft, and as the shaft rotates, the target ring rotates therewith within the first bore. The steering knuckle sensor assembly also includes a speed sensor that defines a distal end. The speed sensor is disposed within the second bore such that the distal end is slightly distanced from the target ring.
In a preferred embodiment, the second bore extends radially from the first bore. Moreover, the assembly includes a holder that is attached to the steering knuckle and engaged with the speed sensor. Preferably, a sensor wire connects the speed sensor to a control module. The control module receives a signal from the speed sensor that represents the speed of the shaft relative to the steering knuckle. In a preferred embodiment, the assembly includes a clip that is attached to the steering knuckle and engaged with the sensor wire.
In another aspect of the present invention, a vehicle braking system includes a master cylinder, a solenoid valve that communicates with master cylinder, and a wheel cylinder that also communicates with solenoid valve. Additionally, the vehicle braking system includes a control module that is connected to the solenoid valve. This aspect of the present invention also includes a steering knuckle sensor assembly. The steering knuckle sensor assembly includes a speed sensor that is connected to the control module. Accordingly, the speed sensor sends a signal to the control module that represents an angular wheel speed.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: